Process for making cerium dioxide nanoparticles

Abstract

A method of improving the efficiency of a diesel engine provided with a source of diesel fuel includes the steps of: a) adding to the diesel fuel a reverse-micellar composition having an aqueous first disperse phase that includes a free radical initiator and a first continuous phase that includes a first hydrocarbon liquid, a first surfactant, and optionally a co-surfactant, thereby producing a modified diesel fuel, and b) operating the engine, thereby combusting the modified diesel fuel. The efficiency of a diesel engine provided with a source of diesel fuel and a source of lubricating oil can also be improved by modifying the lubricating oil by the addition of a stabilized nanoparticulate composition of cerium dioxide. The efficiency of a diesel engine can also be improved by adding to the diesel fuel a reverse-micellar composition that includes an aqueous disperse phase containing boric acid or a borate salt.

What is claimed: 
     
       1. A process of making nanoparticles, comprising:
 (a) forming an aqueous reaction mixture comprising cerous ion, hydroxide ion, an α-hydroxy carboxylic acid, and an oxidant; and 
 (b) heating the reaction mixture to a temperature in the range of about 20° C. to about 100° C., thereby forming a product dispersion of cerium dioxide nanoparticles. 
 
     
     
       2. The process according to  claim 1 , wherein said α-hydroxy carboxylic acid is selected from the group consisting of lactic acid, gluconic acid, tartaric acid, citric acid and 2-hydroxybutanoic acid. 
     
     
       3. The process according to  claim 2 , wherein said α-hydroxy carboxylic acid is lactic acid. 
     
     
       4. The process according to  claim 1 , wherein said reaction mixture further comprises a polyacid. 
     
     
       5. The process according to  claim 4 , wherein said polyacid is ethylenediaminetetraacetic acid. 
     
     
       6. The process according to  claim 5 , wherein said α-hydroxy carboxylic acid is lactic acid and said polyacid is ethylenediaminetetraacetic acid. 
     
     
       7. The process according to  claim 1 , wherein said oxidant is hydrogen peroxide. 
     
     
       8. The process according to  claim 4 , wherein said α-hydroxy carboxylic acid is citric acid. 
     
     
       9. The process according to  claim 8 , wherein said polyacid is ethylenediaminetetraacetic acid.